5G基站对中波广播的干扰处理方法

随着通信技术的快速发展,我国正式进入了5G时代,各运营商获得了5G运营牌照,正在全国各地建设5G基站.然而5G工作频率与广播电视卫星下行C波段的频率存在重合部分,从而会对广播电视节目产生干扰.如何采取科学的方法和有效的措施避开5G基站的干扰,成为当前必须解决的问题,为此,借助一个实例分析5G基站信号对广播电视信号的干扰,提出避开5G基站对广播电视卫星信号干扰方法.     

5G基站对中波广播的干扰处理方法

随着通信技术的快速发展,我国正式进入了5G时代,各运营商获得了5G运营牌照,正在全国各地建设5G基站.然而5G工作频率与广播电视卫星下行C波段的频率存在重合部分,从而会对广播电视节目产生干扰.如何采取科学的方法和有效的措施避开5G基站的干扰,成为当前必须解决的问题,为此,借助一个实例分析5G基站信号对广播电视信号的干扰,提出避开5G基站对广播电视卫星信号干扰方法.     

对一起5G基站干扰的排查分析

目前5G网络建设持续推进,5G基站数量持续增多,5G基站干扰问题也时有发生。本文对一起5G基站干扰案件进行深入分析,以便总结经验,进而提升5G基站干扰排查的效率。     

多路微波分配系统干扰移动5G网络的排查分析

当前5G通信网络建设持续推进,5G基站数量持续增多,5G基站干扰问题也时有发生。本文对一起广电多路微波分配系统（MMDS）设备干扰移动5G基站的案件进行了深入分析,以便总结经验,进而提升5G基站干扰排查的效率。     

700 MHz 5G干扰规避解决方案

中国移动与中国广电700 MHz签署共建共享协议，在全国范围内大规模部署700 MHz 5G移动通信网络。针对700 MHz5GNR基站干扰问题，本文通过700 MHz干扰图谱自动识别定位，实施智选调度、独立解调和上行底噪抑制的干扰规避解决方案，降低带内干扰，保障700 MHz5G通信质量和用户体验。外场测试和后台评估表明，干扰规避措施有效抑制700 MHz部分频段干扰，对于指导700 MHz 5G精品网络工程建设具有参考价值。     

基于基站协作的5G与NGSO星座系统间干扰规避方法研究

针对Q/V频段5G基站与非静止轨道(NGSO)卫星星座系统地球站之间的同频干扰问题,提出了一种基于5G基站协作的干扰规避方法。由多个5G基站组成基站簇,通过簇内基站间协作设置空间隔离来减缓5G基站对地球站的有害干扰。以OneWeb星座系统作为受扰系统,验证了所提方法的干扰减缓效果。结果表明,当干噪比门限值为-12.2 dB时,所提方法能够将OneWeb地球站的干扰发生概率减小30%。     

C频段广播电视卫星通信站抗5G基站干扰的指标分析与效能评估

伴随着5G卫星通信基站在广播电视领域的应用普及，C频段（3.7～4.2 GHz）卫星通信极易受到5G信号干扰现象受到了较多关注。对此，通过分析5G基站干扰机理，给出受扰设备具体影响，进一步解析干扰指标，并计算卫星通信站抗5G干扰的安全距离，最后明确相应的防护措施，为行业采取有效的抗5G基站干扰措施提供参考。     

Q/V频段5G基站对NGSO星座系统地球站的干扰分析

针对Q/V频段5G基站对非静止轨道(Non-geostationary Orbit,NGSO)星座系统地球站的同频干扰问题,提出了一种5G毫米波系统与NGSO星座系统下行链路间的干扰分析方法.结合NG-SO星座系统地球站天线指向的时变性,建立了基于时间离散的"拉远式"和"挖洞式"的动态干扰分析模型,并从强度和集总效应两个维度综合评估了系统之间的干扰情况.以OneWeb系统为例,仿真分析了不同保护距离下5G基站对OneWeb地球站的干扰情况.结果表明,在Q/V频段,当保护距离为50 m时,95％ 的时间内干扰余量不小于15.38 dB,5G基站与NGSO星座系统地球站有兼容共存的空间.     

C波段中波广播转播台抗5G基站干扰分析及实践

介绍中波广播转播台卫星接收系统的工作原理,着重介绍高频头、接收机等设备,分析5G基站对C频段卫星接收系统产生干扰的原因,并分析其对高频头、接收机等设备产生的干扰,从3个方面提出切实可行的中波广播转播台抗5G基站干扰的改造措施,结合抗5G基站干扰的具体措施进行详细说明,指出改造时需要注意的两点问题,为今后各个中波广播转播台对C频段卫星接收设备进行改造提供借鉴和参考.     

排查5G基站对卫星电视干扰的若干思考

5G商用后,5G基站对卫星电视的干扰时有发生。本文通过两个典型的干扰案例,探讨了5G基站对卫星电视业务的干扰排查及协调方法,思考在5G时代更复杂的无线电环境中,如何进一步优化相关机制,尽快排查并协调解决,促进无线电业务健康有序发展。     

一种适用于多用户OFDM系统下行链路的跨层设计调度算法

该文提出了一种适用于多用户正交频分复用(OFDM)系统下行链路的调度算法,基于跨层结构设计,并分别考虑了媒体接入控制(MAC)层的用户服务质量(QoS)要求、用户公平性、数据包队列状态信息以及物理层的信道状态信息(CSI)和功率约束等。多用户OFDM系统可以通过该调度算法充分利用MAC层和物理层的不同参数特性,在保证用户QoS的同时最大化频谱的利用效率。仿真结果表明,在小区内各个移动用户具有不同的接收SNR的情况下,该算法具有服务质量随信噪比波动平缓、丢包率低、实现复杂度低等特点。     

多用户MIMO-OFDMA系统混合业务的跨层分组调度算法

该文提出了一种针对多输入多输出-正交频分多址系统混合业务的跨层分组调度算法。该算法基于物理层的信道状况和媒体接入控制子层用户的排队时延,分别为实时业务用户和非实时业务用户的排队时延构建相应的效用函数,以保障不同业务的服务需求。仿真结果表明:该算法不但能保证实时业务的时延需要,而且能够获得很好的吞吐量,并满足公平性要求。     

基于RSS相关性的位置指纹室内定位方法

解决设备差异性造成的Wi-Fi信号强度不确定问题是位置指纹室内定位应用与推广的关键.一种基于设备间接收信号强度(Received Signal Strength,RSS)相关性的位置指纹室内定位方法被提出.以智能手机为用户终端,离线阶段,通过智能手机扫描的Wi-Fi信号强度信息,经过数据处理,筛选稳定的接入点(Access Point,AP),构建离线指纹数据库;在线定位阶段,对于实时获取的Wi-Fi信号强度信息,进行筛选处理后,挑选与离线指纹共同拥有的AP,并根据该AP集合,形成新的离线指纹和在线指纹.对离线指纹按RSS的大小降序排序;在线指纹,则以同一次序对RSS排序,然后利用皮尔逊相关系数和杰卡德相似系数,计算指纹相似度并排序,通过K最近邻(K-Nearest Neighbor,KNN)算法实现用户定位.实验表明该方法可有效解决设备差异性问题,并实现精确定位,平均定位误差达到1.7 m.     

多用户大规模MIMO自适应安全传输策略

大规模MIMO系统采用空分多址可以提高系统吞吐量,同时利用多用户下行信号的相互协作可以对窃听者造成叠加干扰,带来了天然的安全增益。但目前该系统的物理层安全研究仍采用传统的人工噪声方案,忽略了多用户信号干扰带来的安全增益,造成严重的功率浪费。针对这一问题,该文分析了多用户信号干扰对系统可达平均安全速率和平均安全能效的影响,给出了系统的最佳接入用户区间。研究发现,在系统接入用户数较少和用户数较多时,系统安全能力较弱,针对此分别提出了N波束加扰和基于用户位置的用户调度的自适应安全传输策略。最后通过仿真验证了理论推导和所提策略的有效性,利用该文所提策略,能够保证系统天然安全能力不足时的安全通信。     

Resource allocation based on cross-layer QoS-guaranteed scheduling for multi-service multi-user MIMO–OFDMA systems

Cross-layer strategies for resource allocation in wireless networks are essential to guaranty an efficient utilization of the scarce resource. In this paper, we present an efficient radio resource allocation scheme based on PHY/MAC cross layer design and QoS-guaranteed scheduling for multi-user (MU), multi-service (MS), multi-input multi-output (MIMO) concept, orthogonal frequency division multiple access (OFDMA) systems. It is about a downlink multimedia transmission chain in which the available resources as power and bandwidth, are dynamically allocated according to the system parameters. Among these parameters, we can mention the physical link elements such as channel state information, spectral efficiency and error code corrector rate, and MAC link variables, which correspond to the users QoS requirements and the queue status. Primarily, we use a jointly method which parametrizes these system parameters, according to the total power, and the bit error rate constraints. Secondly, we propose a QoS-guaranteed scheduling that shares the sub-carriers to the users. These users request several type of traffic under throughput threshold constraints. The main objective in this work is to adjust the average throughput per service of each user, according to their needs and likewise to satisfy a great number of connexions. Subsequently, we consider a model of moderated compartmentalization between various classes of services by partitioning the total bandwidth into several parts. Each class of service will occupy a part of the bandwidth and will be transmitted over a maximum number of sub-carriers. The simulation results show that the proposed strategy provides a more interesting performance improvement (in terms of average data rate and user satisfaction) than other existing resource allocation schemes, such as nonadaptive resource allocation strategy. The performances are also analyzed and compared for the two multi-service multi-user MIMO–OFDMA systems; with sub-carriers partitioning and without sub-carriers partitioning.     

密集网络中基于拓扑信息的用户调度与干扰管理

随着未来移动通信网络的密集化,如何利用少量的信道信息有效管理小区间干扰成为一个重要而又棘手的问题。本文面向密集多小区多用户单天线和多天线网络,研究利用拓扑信息协调小区间干扰的传输策略。为了解决不同小区多用户调度间的冲突,把用户调度与干扰管理收发机设计进行统一建模,基于统一模型引入潜在冲突图,并利用潜在冲突图进行拓扑干扰管理,提出了占用系统资源最少的传输策略。仿真结果表明,与先进行用户调度再协调小区间干扰的方法相比,所提出的方法在用户平均数据率和边缘用户数据率方面都能够获得显著的性能增益。      

An overview of scheduling algorithms in MIMO-based fourth-generation wireless systems

In this article an overview of the scheduling algorithms proposed for fourth-generation multiuser wireless networks based on multiple-input multiple-output technology is presented. In MIMO systems a multi-user diversity gain can be extracted by tracking the channel fluctuations between each user and the base station, and scheduling transmission for the "best" user. Based on this idea, several opportunistic scheduling schemes that attempt to improve global capacity or satisfy users with different QoS requirements have been proposed. Transmit beamforming procedures aimed at increasing the channel fluctuations have been proposed. The simultaneous exploitation of both spatial and multi-user diversity is not straightforward; however, it may be achieved by a refined selection of the "best" user. In addition, a multiple access gain can be obtained from a simple SDMA/TOMA system. Finally, several resource allocation schemes are discussed for this hybrid multiple access system.     

基于QoS保证的多用户OFDM系统跨层资源分配

针对正交频分复用(OFDM)系统资源分配和调度问题,提出一种基于第三代移动通信长期演进(LTE)系统的分块跨层资源分配算法。此算法考虑物理层的信道状态信息、媒体接入层(MAC)的有限用户缓存队列长度、用户的丢失率和时延等QoS要求,以提高系统频谱效率为总体目标。通过从实时视频业务和混合业务两种业务类型下进行大量对比分析,得出提出的算法能有效提高系统的频谱效率和降低系统时延。     

Coordinated User Scheduling Based on Hybrid CSI in Multi-User MIMO Relay System with Limited Feedback

This paper considers coordinated user scheduling in a multi-user two-hop multi-input multi-output relay system with limited feedback. The proposed scheme utilizes a quantized transmit correlation and channel quality information, enabling to achieve both interference mitigation and multi-user diversity (MUD) gain. To this end, we first investigate the effect of quantization error on the statistical characteristics of co-channel interference (CCI) cased by the relay. Then, the coordinated user-scheduling strategy is designed with the use of eigen-beamforming to maximize the desired signal power in an instantaneous manner while minimizing the CCI in an average sense. Analytic and numerical results show that the proposed scheme can maximize the achievable sum-rate by handling a tradeoff between interference mitigation and MUD gain according to the number of quantization bits, providing a large sum-rate performance in the presence of quantization error.     

A Dynamic Resource Allocation Scheme for the Downlink Heterogeneous Traffic of Internet Protocol (IP) Based OFDM networks

Radio Resource management mechanisms such as physical-centric radio resource allocation and medium access control (MAC)—centric packet scheduling are expected to play a substantial role in the performance of orthogonal frequency division multiplexing (OFDM) based wireless networks. OFDM provide fine granularity for resource allocation since they are capable of dynamically assigning sub-carriers to multiple users and adaptively allocating transmit power. The current layered networking architecture, in which each layer is designed and operated independently, results in inefficient resource use in wireless networks due to the nature of the wireless medium, such as time-varying channel fading. Thus, we need an integrated adaptive design across different layers, allowing for a cross-layer design. In this paper, a scheduling scheme is proposed to dynamically allocate resources for the downlink data transmission of internet protocol based OFDM networks. Generally to maximize the capacity and user satisfaction improvements in packet data admission, scheduling and policing are necessary. Of the three, efficient scheduling has the greatest impact on increased system capacity or effective spectrum usage. In addition, proper scheduling can greatly improve user satisfaction. The contribution of this work is twofold: first we evaluate current allocation schemes by exploiting the knowledge of channel sate information (CSI) and traffic characteristics in terms of queue state information (QSI) to acquire the system performance on a real time network. Second, the resource allocation scheme is extended by incorporating MAC layer information as well as opportunistic packet scheduling in the time-domain-based on minimum weight cost function. The key factors that affect the overall system performance in terms of system average throughput and delay are identified, evaluated and discussed.